Fluid-pressure brake.



No. 777,105. PATENTED DEC. 13, 1904. A. KAPTEYN FLUID PRESSURE BRAKE.

APPLICATION FILED FEB. 18, 1903.

NO MODEL.

l l'o,'777,105. Patented. December i3, 190%.

llhviirien diaries ldairierrr ALBERT KAI." EYN, OF ilrOlNlJOll, ENGLAND, ASFlGNOR TO Tlll l Wlttl'lllllill- HOUSE AIR BRAKE COMPANY, OF Plil'ltiBUltU, Pl lNNrlYLVANlr-i, A COR,- PORATION OF PENNSYLVANIA.

FLUIID WWIESSUHIE lEillW dltE SPECIFICATION forming part of Letters Patent No. 777,105, dated lDeoember 13, 1904i.

Application filed February 18, 1908. Serial No. 143,953. (No model.)

T 017/3 11171101" it y or law which may be determined by further Be it known that I, ALBERT KAPTEYN, a sub- (BXl'lGl'lll'lODi).

ject of the Queen of the Netherlands, residing The object of this invention is to indicate at London, England, have invented a certain means by which the maximum degree or ores- 5 new and useful Improvement in Flllld-PFGS- sure-in the brakecylinder can be made to vary sure Brakes, ofwhichimprovement the i'ollowautriunatically in accordance with the speed or ing is a specification. with any law which maybe "found to give the Thisinvention relates to lluuhpressure brake highest possible brake elliciency. apparatus-for railway and like vehicles, and in the accompanyingdrawings, Flgure l is 10 especially to that type of apparatus in which a view showing diagrammatical1y one form oi the pressure of the brake-shoes on the wheels my improvement, and Fig. 2 is asimilar diais controlled by the speed of the vehicle. grammatic view showing a modification. 6

It is well known that the coetlicient of fric- The invention is applicable to any term of tion between the brake-shoes and wheels of a fluid-pressure brake apparatus, and as these 5 vehicle varies in accordance with the speed of are now well known it is not necessary to dothe vehicle. Hence it is necessary in order scribe them in detail. Brake apparatus oii to secure an adequate braking effect that this character comprises, essentially, a brakewith an increased speed of the vehicle the cylinder provided with a piston, the rod of brakes should be applied with a correspondwhich is'attached to the levers or other mech- 20 ing increase of pressure. lit is also well known anism for applying the brakes, and the brakes that at every speed there is a certain pressure are applied by admitting lluid under prcssu re on the brake-shoes which will just suiiice to to the brake-cylinder, thereby actuating its 7 lock them with the wheel, and thereby skid piston and applying the brake-shoes to the the wheel on the rail, and it is exceedingly wheels.

' 5 important in brake apparatus to so adjust the Referring now to Fig. 1, a shaft 1 mountvarious parts as not to allow the pressure of ed in suitable bearings liked to any convenient the brake-shoes on the wheels to become so part of the vehicle and is adapted to be rotated great as will allow this to take place. The from a revolving part of the vehicle,- such as reason for this is that when the wheel skids the wheels or theaxle, by anysuitable means 3 on the rail the braking efl'ect is greatly resuch, for instance, as toothed gearing or a duced and also when this is allowed to hapbelt and pulley, a friction-disk, or the like. pen flats are produced on the wheel, which is The shaft 1 is provided with a fixed collar 2 thereby rendered unfit for service. and a movable collar 3, these being pivotally It has heretofore been proposed to use a connectedtogether by doublelinksai These 35 centrifugal governor for varying the force links are provided at their central pivotal with which an escape-valve is held to its seat; points with weights 6, and the collars E2 3 are but in this case the degree of brake-cylinder arranged to be pressed apart by means of a 5 pressure at which the valve opens varies acspring 7, inserted between themand surroundcording to the centrifugal force of the goving the shaft 1. The apparatus thus i'ar de- 4 ernor and not in accordance with the speed of scribed a centrifugal governing device 01'' a the car, since the centrifugal :lorce varies as well-known character; but i wish it to he unthe squares of the corrcspoinling speeds. derstood that the invention is not limited to 9 Various experiments which have been made this or any other form oli governing device, seem to indicate that in order to obtain the as any suitable type of governor may obvi- 45 highest possible brake eflieiency the pressure ously be employed. Pivotally attached to the in the brake-cylinder should'not vary accordlower collar 3 is a lever 9, mounted at its con ing to the square of the speed, butmore nearly tral point 8 in a bearing secured to the vehidirectly as the speed or according to some rule ole, and is so arranged as to respond to every means of a link 12 to the other end of the lever 9. Firmly secured to this sliding plate 11 is another plate 13, which projects beyond the guide-bracket 10 and is curved at its outer end, thus providing a cam-surface for a purpose which will hereinafter appear. Connected to a convenient part of the brake-cylinder 28 and communicating with the interior thereof by a pipe 29 is a casing 1 1, provided with an exhaust-valve 15, said valve being held against its seat by means of a load device, such as spring 16. This spring surrounds the stem 17 of the valve 15 and abuts against a plunger 18, which is arranged to slide in an orifice in the other end of the casing let. The end of the plunger 18 which projects through the casing 14 is provided with a wheel or pulley 19, adapted to engage with the curved portion of the plate 13. The casing 1 1 is also provided with an orifice 20, leading to the atmosphere, so that when the valve 15 is lifted from its seat fluid under pressure from the brake -cylinder may exhaust to the atmosphere.

The operation of the device is as follows: It will be clear that the governor will take up a definite position of equilibrium for every speed. at which it revolves, this speed of course corresponding to the speed at which the vehiele is traveling. These various positions are communicated by means of the lever 9 and link 12 to the curved plate 13, which will consequently also take up a definite position corresponding to every variation in the speed of the vehicle. As the curved plate 13 is moved the sliding plunger 18 will be correspondingly moved, thereby altering the tension of the spring 16, and consequently the load on the valve 15. It is clear that the curve of the plate 13 may be made in such a way as to accurately express the law of greatest brake efiiciency, and the shape of the curve or cam surface may be determined, if necessary, by

practical experiment.

spring 16 on the valve 15 and the amount of variation in the load on the spring by means of the plunger 18 and curved plate 13 will be so adjusted as to secure this result, if necessary, by a process of trial and error.

In 2 of the drawings I have shown an example of how the device may be modified. In this case the lever 9 carries a link 12, which is attached to a roller 25, mounted at the end of the link 21, and to this link is attached the spring 16, which is secured at its other end to some fixed portion of the vehicle. In place of the sliding plate 13 the cam-surface is secured by means of a curved lever 22, which is pivotally attached at one end, 23, to a fixed part of the vehicle and is adapted to bear at its other end against the roller 25. L The exhaust-valve 15 is held against its seat by means of a pointed arm 24, pivotally attached to the curved lever 22. The curve of the lever 22 may be determined in the same way as the curve of the plate 13that is to say, by practical experiment. In this form of the device it will be seen that as the link 12 moves up and down in accordance with the movement of the lever 9, due to the varying position of the governor, the tension of the spring 16, as well as its leverage, will be altered, and conseqently the load on the valve 15 will vary in accordance with the various positions of the governor. In all other respects the operation of the device is similar to that described in Fig. 1.

It will now be seen that I have provided an intermediate element or connection, such as a cam-surface,between the centrifugal governor or other speed-controlled device and the load device acting on the valve, and also that such cam-surface may be varied so as to give any desired relation between the centrifugal force or speed and force acting on the valve, whereby the pressure of the brake-shoes may be automatically varied in accordance with the speed or with any law governed by the speed, as may be desired.

I wish it to be clearly understood that the constructions described above are only shown by way of example, and I do not limit myself to any particular construction, as many may be devised which will achieve the same object, and all are intended to be included within the scope of my invention.

Having now described my invention, what I claim as new, and desire to obtain by Letters Patent, is

1. In a fluid-pressure brake, the combination with means for regulating the pressure with which the brakes are applied, of a speedcontrolled device and a variable intermediate element acting on said regulating means, whereby the braking force may be varied in accordance with the speed of the car, or any desired function thereof. I

2. In a fluid-pressure brake, the combination with a valve for regulating the brake-cylinder pressure, of a speed-controlled device and a variable intermediate element for varying the effect of the said speed-controlled device upon the valve.

3. In a fluid-pressure brake, the combination with a valve for regulating the brake-cylinder pressure, and a load device acting; on said valve, of a speed-controlled mechanism operating to vary the effect of the lead device upon the valve.

4. In a fluid-pressure brake, the combination with an exhaust-valve for regulating the brake-cylinder pressure, of a speed-controlled device and a variable intermediate element operated by said speed-controlled device for varying the effect of the speed-controlled device upon the valve.

5. In a fluid-pressure brake, the combination With an exhaust-valve for regulating; the pressure in the brake-cylinder, and a load device acting on said valve, of a speed-controlled mechanism and a variable intermediate element connected to said speed-controlled mechanism and bearing on said lead device.

ALBERT KAPTEYN.

WVitnesses:

EMIL VoL'r, F. Bossnanorrn. 

